Electric circuit breaker



Nov. 24, 1964 L. P. KOVAL 3,158,716

ELECTRIC CIRCUIT BREAKER 2 Sheets-Sheet 1 Filed July 17, 1962 FIG.

65 6A 27 '0 7 l3 I5 I ll GA w 3 e 3 FIG. 2

INVENTOR. L EONIDE'. KOVAL WMYTC'UV ATTORNEY L. P. KOVAL ELECTRICCIRCUIT BREAKER 2 Sheets-Sheet 2 "TmPPao" FlG.3

INVENTOR. LEONIDE. ID. KOVAL fimjf y A TTORNEY Nov. 24, 1964 Filed July17, 1962 FI G.4-

United States Patent 3,158,716 ELECTRlC CIRCUIT BREAKER Leonide l Koval,Far Rockaway, N.Y., assignor to General Electric Company, a corporationof New York Filed July 17, 1962, 581'. No. 216,375 t Claims. (Cl. 200136) My invention relates to electric circuit breakers, and particularlyto electric circuit breakers of the type in cluding a contact armoperated by a pair of toggle links, the toggle links being supported ona releasable support or cradle.

In circuit breakers of the type described, it has been found that whenthe parts are constructed and arranged to provide maximum contactpressure in the closed position, it is necessary to provide means formaintaining the toggle links in at least a partially collapsed conditionwhen tripping occurs. This is necessary to provide a desired bias forceto move the breaker handle to tripindicating position, and also to movethe movable contact to a maximum open position.

in accordance with the prior art, such means has been providedcomprising a portion of the toggle-support or cradle member, adapted toengage the toggle links upon tripping, to maintain the toggle links inpartially collapsed condition.

Such construction requires that the releasable support and the togglelinks be so constructed and arranged that the desired inter-action cantake place. Such construction and arrangement, however, may not bedesirable from the point of ease of assembly, and avoidance of highlyconcentrated forces.

It is an object of the present invention to provide an electric circuitbreaker having an operating mechanism of the type described includingmeans for maintaining the operating toggles in partially collapsedcondition upon tripping without the necessity of inter-action betweenthe releasable support members and the toggle.

It is another object of the invention to provide an electric circuitbreaker having an operating mechanism of the type described includingmeans for maintaining the operating toggles in partially collapsedcondition upon tripping, which does not require the use of additionalmovable parts in the mechanism.

In accordance with the invention in one form, a circuit breakeroperating mechanism is provided including a support and at least onecontact arm pivotally supported on the support. For operating thecontact arm, a pair of toggle links are provided. One end of the togglelinkage is pivotally supported on the contact arm. The other end of thetoggle linkage is pivotally supported on a releasable support or cradle,which is pivotally sup ported on the support at one end and releasablylatched with respect to the support at the other end. An operatingspring is provided, having one end connected to the knee of the togglelinkage and the other end carried by an arcuately movable handle member.

in accordance with the invention, the toggle link connected to thecontact arm is provided with an extension which, in the trippedcondition, engages a rigidly mounted stop which limits movement of thelower toggle link toward straightened condition.

The invention will be more fully understood from the following detaileddescription, taken in conjunction with the accompanying drawings, andits scope will be pointed out in the appended claims.

FIGURE 1 is a side elevation view of an electric circuit breakerincorporating the invention, portions of the casing being broken away,the parts being shown in the OFF condition;

FIGURE 2 is a side elevation View of the mechanism of FIGURE 1, theparts being shown in the ON condition;

FIGURE 3 is a side elevation view of the mechanism of FIGURE 1, theparts being shown in the TRIPPED condition;

FIGURE 4 is an end elevation view of a portion of the circuit breakermechanism, taken generally on the line 4-. of FTGURE 3, and

FlGURE 5 is an exploded perspective view of a portion of the mechanismor" the circuit breaker of FIG URE 1.

Referring to FIGURE 1, the invention is shown as incorporated in anelectric circuit breaker comprising an insulating casing including abase 2 and a cover 3. The casing 1 is generally rectangular and includesthree line terminals (not shown) at one end, and three load terminals(not shown) at the other end. Electrical continuity between each pair ofcorresponding line and load terminals is adapted to be controlled by apair of contacts including a relatively movable contact 4 and astationary contact 5 (only one pair shown).

Each of the movable contacts 4 is carried by a movable contact support6, which is pivotally connected to a contact arm 7 by pivot pin 14. Theforward end of the contact support 6 has a post 6A extending through thecontact arm 7. A compression spring 6A is positioned on post 6A betweenthe support 6 and t e arm 7, and a cotter pin 63 limits movement of thesupport 6 away from arm 7. The contact support 6 has a flexibleconnector connected thereto adjacent the pivot pin 14 by suitable meanssuch as by brazing. The contact arm 7 for the center pair of line andload terminals, as illus trated in FIGURE 1, is pivotally supported onpin 8 carried by side plate portions of a stationary frame assembly 9.

The contact arm 7 for each pair of line and load terminals is anchoredby suitable fastening means 10, to a contact cross-arm ll of reinforcedinsulating material. Thus movement of the center contact arm '7 carrieswith it the two outside contact arms.

For the purpose of operating the center contact arm 7 between open andclosed circuit positions, operating mechanisms is provided including atoggle linkage comprising a side-by-side pair of upper toggle links 12,and a pair or" lower toggle links 13. The lower toggle links l3 compriseportions of a singlebifurcated member, as shown particularly in EEGURE4, and are pivotally connected to oppose depending side portions of thecontact arm '7 by the pivot pin 14.

The upper toggle links 12 are connected to the lower toggle links 13 byknee pivot pin 15. The upper toggle links 12 are also connected by pivotpin 16 to a releas able support or cradle member 117.

The cradle member 17 is pivotally supported at one end of the supportframe 9 by pivot pin 18. The cradle member 1? is releasably latched atits other end by a suitable latch member 19. The latch member 19 isadapted to be moved or permitted to move to releasing position bysuitable current-responsive means, not shown.

The toggle linkage comprising links 12 and 13 is adapted to be operatedbetween collapsed and straightened conditions by means of a manuallyoperable handle member 20, carried by a handle support member 21.

The handle support member 21 is generally bifurcated or U-shaped, and ispivotally supported on the sides of the frame member 9 on pivotsupports, not shown.

Movement of the handle member Ell from the position shown in FIGURE 1 tothe position shown in FIGURE 2 moves the operating spring 22 which isconnected between the handle support member 21 and the knee pivot pin 15of the toggle linkage, across the line of centers of pivot pins 15 and16, and moves the toggle linkage from collapsed position as in FIGURE 1to straightened position as in FIGURE 2 with a snap action. This alsomoves the movable contacts 4 to closed circuit position as shown inFIGURE 2.

Upon the occurrence of predetermined current conditions through thecontacts 4 and 5, the member 17 is released from the latch 19 and theparts thereupon move to the position shown in FIGURE 3.

For the purpose of maintaining the toggle links in a more collapsedposition than they would otherwise assume when tripping occurs, thelower toggle links 13 are each made generally L-shaped, having anextension 13'. The frame member 9 is provided with a pair of rigidlymounted stops or pins 24, each extending inwardly from one side of theframe 9. The stop pins 24 are further sup ported by means of auxiliarysupport members 24A as shown particularly in FIGURES 4 and 5. Each piece24A includes a bent-over portion 243 which fits over the lower edge ofthe frame-side 9. This, together with hole 24C, which fits over the endof pin 8, retains the piece 24A in position. The pin 24 extends throughthe hole 24D as well as through an aligned hole in the side of the frame9. On release of the cradle 17, the parts move from the position shownin FIGURE 2 to the position shown in FIGURE 3. It will be observed thatthe toggle links, including the pins 14 and 16, move generally upwardlyat this time. As this occurs, the extensions 13 of the toggle links 13engage the stop members 24- carried by the frame 9, and cause the links13 to rotate slightly clockwise about their pivot M.

This maintains the knee 15 of the toggle linkage in a position offsetslightly to the right as viewed, and has the dual effect of causing theoperating spring 22 to exert more of a bias on the handle 20, tending tomove it to midor trip-indicating position, and of moving the contact armto fully open position, in which it engages the member 27, surroundingthe pivot pin 18, as a stop.

In order to reset the mechanism, the handle is moved clockwise asviewed, causing the handle support member 21 to engage the cradle 17,rotating it clockwise until the portion 17 re-engages the latch member19. The mechanism is then re-set and can be reclosed by moving thehandle in counterclockwise direction.

The depending side portions of the channel-shaped contact arm 7 areprovided with cut-away recesses or notches 7 to afford clearance for thestop pins 24.

It will be observed from FIGURE 4 that the ends 13' of the lower togglelink engage the pins 24 at a portion spaced from the inner surface ofthe frame 9, due to the fact that clearance must be afforded for thesides of the channel-shaped contact arm '7.

Also, it will be observed that the pins 24 cannot be made unitary, i.e.,part of a single pin going between the sides of frame 9 due to the factthat space must be left for the flexible conductor 6C (see FIGURE 4).Thus there is a tendency for the pins 2 to be tilted from theirsupported ends under the impact of ends 13' when tripping occurs. Thereinforcing pieces 24A support the pins 24 at the opposite side of theframe 9 and prevent such tilting.

While the invention has been shown in one particular embodiment, it willbe readily appreciated that many modifications thereof may be made, andI therefore intend, by the appended claims, to cover all suchmodifications as fall within the true spirit and scope of the invention.

What I claim as new and desire to secure by Letters Patent of the UnitedStates is:

1. An electric circuit breaker comprising:

(a) a support,

(12) at least one movable contact arm pivotally supported on saidsupport,

(0) operating means for operating said movable contact arm between openand closed circuit positions, said operating means comprising areleasable togglesupporting member pivotally supported on said support,

(a!) upper toggle links pivotally connected to said releasable supportat one end,

(e) a pair of lower toggle links pivotally connected to said movablecontact arm at one end,

(1) a knee pin interconnecting said upper and lower toggle links,

(g) a handle member pivotally supported on said support,

(11) an operating spring having one end connected to said handle memberand its other end connected to said knee pin of said toggle linkage,

(i) latch means normally restraining said releasable toggle-supportingmember in latched position and operable in response to predeterminedcurrent conditions to release said releasable toggle-supporting member,

(j) stop means rigidly attached to said support and spaced from saidpivotal connection of said toggle links to said contact arm, and

(k) said lower toggle links including means engaging said stop meansfollowing release of said releasable means and maintaining said togglelinkage in a partially collapsed position following release of saidreleasable means.

2. An electric circuit breaker comprising:

(a) a support,

(b) at least one movable contact arm pivotally supported on saidsupport,

(0) operating means for operating said movable contact arm between openand closed circuit positions, said operating means comprising areleasable togglesupporting member pivotally supported on said support,

(d) upper toggle links pivotally connected to said releasable support atone end,

(2) a pair of lower toggle links pivotally connected to said movablecontact arm at one end,

(7) a knee pin interconnecting said upper and lower toggle links,

(g) a handle member pivotally supported on said support,

(h) an operating spring having one end connected to said handle memberand its other end connected to said knee pin of said toggle linkage,

(i) latch means normally restraining said releasable toggle-supportingmember in latched position and operable in response to predeterminedcurrent conditions to release said releasable toggle-supporting member,

(j) stop means rigidly attached to said support between said pivot ofsaid contact arm on said support and said pivotal connection of saidtoggle links and said contact arm, and

(k) said lower toggle links including means engaging said stop meansfollowing release of said releasable means and maintaining said togglelinkage in a partially collapsed position following release of saidreleasable means.

3. An electric circuit breaker comprising:

(a) a support,

(b) at least one movable contact arm pivotally supported on saidsupport,

(0) operating means for operating said movable contact arm between openand closed circuit positions, said operating means comprising areleasable togglesupporting member pivotally supported on said support,

(d) upper toggle links pivotally connected to said releasable support atone end,

(e) a pair of lower toggle links pivotally connected to said movablecontact arm at one end,

( a knee pin interconnecting said upper and lower toggle links,

(g) a handle member pivotally supported on said support,

(/1) an operating spring having one end connected to said handle memberand its other end connected to said knee pin of said toggle linkage,

(i) latch means normally restraining said releasable toggle-supportingmember in latched position and operable in response to predeterminedcurrent conditions to release said releasable toggle-supporting member,

( j) said toggle links including a first toggle link connected to saidcontact arm, said first toggle link including an offset portionextending generally at right angles to the remaining portion, and

(k) stop means rigidly attached to said support between said pivot ofsaid contact arm on said support and said pivotal connection of saidtoggle links and said contact arm, and

(m) said offset portion of said toggle links being engageable with saidstop means following release of said releasable means to maintain saidtoggle linkage in a partially collapsed position.

4. An electric circuit breaker comprising:

(a) a support,

(b) at least one movable contact arm pivotally supported at a firstpoint thereof on said support,

(c) operating means for operating said movable contact arm between openand closed circuit positions,

said operating means comprising a releasable toggle supporting memberpivotally supported on said support,

((1) at least one upper toggle link pivotally connected to saidreleasable support at one end,

(e) at least one lower toggle link pivotally connected to said movablecontact arm at a second point on said contact arm spaced from said firstpoint,

(f) a knee pin interconnecting said upper and lower toggle links,

(g) a handle member pivotally supported on said support,

(h) an operating spring having one end connected to said handle memberand having its other end connected to said knee pin of said togglelinks,

(1') latch means normally restraining said releasable toggle supportingmember in latched position and operable in response to predeterminedcurrent conditions to release said releasable toggle supporting member,

(j) said lower toggle link including a portion extending generally atright angles to the remaining portion from said second point generallytoward said first point,

(k) stop means fixedly carried by said support adjacent said first pointof said contact arm,

(m) said right angles extending portion of said lower toggle linkengaging said stop means and maintaining said toggle in a partiallycollapsed position following release of said releasable means.

References Cited in the file of this patent UNITED STATES PATENTS2,195,016 Swingle Mar. 26, 1940 2,455,753 Getchell Dec. 7, 19482,492,009 Sandin et a1, Dec. 20, 1949 3,003,046 De Torre Oct. 3, 1961

1. AN ELECTRIC CIRCUIT BREAKER COMPRISING: (A) A SUPPORT, (B) AT LEASTONE MOVABLE CONTACT ARM PIVOTALLY SUPPORTED ON SAID SUPPORT, (C)OPERATING MEANS FOR OPERATING SAID MOVABLE CONTACT ARM BETWEEN OPEN ANDCLOSED CIRCUIT POSITIONS, SAID OPERATING MEANS COMPRISING A RELEASABLETOGGLESUPPORTING MEMBER PIVOTALLY SUPPORTED ON SAID SUPPORT, (D) UPPERTOGGLE LINKS PIVOTALLY CONNECTED TO SAID RELEASABLE SUPPORT AT ONE END,(E) A PAIR OF LOWER TOGGLE LINKS PIVOTALLY CONNECTED TO SAID MOVABLECONTACT ARM AT ONE END, (F) A KNEE PIN INTERCONNECTING SAID UPPER ANDLOWER TOGGLE LINKS, (G) A HANDLE MEMBER PIVOTALLY SUPPORTED ON SAIDSUPPORT, (H) AN OPERATING SPRING HAVING ONE END CONNECTED TO SAID HANDLEMEMBER AND ITS OTHER END CONNECTED TO SAID KNEE PIN OF SAID TOGGLELINKAGE, (I) LATCH MEANS NORMALLY RESTRAINING SAID RELEASABLETOGGLE-SUPPORTING MEMBER IN LATCHED POSITION AND OPERABLE IN RESPONSE TOPREDETERMINED CURRENT CONDITIONS TO RELEASE SAID RELEASABLETOGGLE-SUPPORTING MEMBER, (J) STOP MEANS RIGIDLY ATTACHED TO SAIDSUPPORT AND SPACED FROM SAID PIVOTAL CONNECTION OF SAID TOGGLE LINKS TOSAID CONTACT ARM, AND (K) SAID LOWER TOGGLE LINKS INCLUDING MEANSENGAGING SAID STOP MEANS FOLLOWING RELEASE OF SAID RELEASABLE MEANS ANDMAINTAINING SAID TOGGLE LINKAGE IN A PARTIALLY COLLAPSED POSITIONFOLLOWING RELEASE OF SAID RELEASABLE MEANS.